LAKE FOREST, Ill. (CBS) – Toughness — or a lack thereof — was a theme for the Bears’ three-day minicamp that wrapped up Thursday. It’s the essential improvement needed for a defense that in 2013 set records for futility in the franchise’s long history.

Bears coach Marc Trestman harped on toughness to the press after Wednesday’s practice at Halas Hall. Cornerback Tim Jennings was in full agreement, speaking out on Thursday.

“We weren’t tough at all,” Jennings said. “We couldn’t stop anybody. Running backs we had never heard of were rushing for over 100 yards. That’s not toughness at all. We take (Trestman’s comments) as the truth. We take it as a slap in the face.”

A revamped unit will alter this issue, the Bears hope. Veterans like Jared Allen, Lamarr Houston, Willie Young and Israel Idonije were brought in to shore up a defensive line that struggled to generate any pressure. In the secondary, where the Bears’ defense often broke down, rookies Kyle Fuller and Brock Vereen and free-agent signings M.D. Jennings and Ryan Mundy were brought in with a core of Charles Tillman and Jennings.

In order to establish the Bears’ past with the present, Trestman brought in team greats to speak with the players.

“There’s a way to play football in Chicago — that’s being tough and physical,” Trestman said.

It’s something that resonated with the Bears. Trestman can only hope the difference is seen on Sundays in the fall.

Vereen fitting right in

Rookie safety Vereen is just thrilled to be a Chicago Bear. It’s the kind of opportunity any football player would dream of. The former Minnesota standout is getting his chance.

“It still hasn’t fully hit me,” Vereen said. “I’m still trying to show that I can be a contributing factor to the team.”

However, Vereen has taken it further than that. Just a rookie in his first full mini-camp, he’s getting significant reps with the Bears’ first-team defense.

It’s just practice reps in June, with the team wearing shorts and shirts, no pads, but Trestman suggests it’s something significant.

“The simple fact we’ve rotated him with the ones is a clear indication that we think he can compete,” Trestman said. “But we’re not going to anoint him.”

Praise from the coaching staff is something Vereen has learned to tune out. He just doesn’t want to hear it. Instead, he takes the mistakes personally and uses them to improve.

“I don’t really focus on the positive stuff,” Vereen said. “I kind of beat myself up a little bit. The coaches have seemed positive (about my play) for the most part. I hope that’s the case.”

Added Trestman: “Brock has not looked out of place. He certainly has room to grow, but he’s very highly football intelligent.”

With returning starting safety Chris Conte sidelined from mini-camp as he recovers from shoulder surgery, Vereen has gotten his chance to work in with the ones, alongside new free-agent acquisitions Jennings and Mundy.

Should Vereen’s strong play continue in training camp, he’ll still be with the top guns in Week 1.

Weems wants to return kicks

Every time Devin Hester stepped back for a return, fans at Soldier Field felt he could take it to the house. Opposing teams were ready for a challenge in stopping the speedster.

Now, Hester is gone, and the Bears must find their next return specialist. Eric Weem wants the chance to shine.

“I feel like I can dominate the position,” Weems said. “I just have to be given the opportunity. Once I get my chance, I have to make the most of it.”

Now in his third year with the Bears, Weems is considered the leader of the special teams unit. He has a close relationship with special teams coach Joe DeCamillis, and the two are on the same page. Even so, he’s not free from criticism.

“Me being the leader of the special teams group, he expects much of me,” said Weems. “If I do something wrong, he’s going to get on me as well.”

There’s steady competition to replace Hester as the Bears’ return man. Names like Chris Williams, Armanti Edwards and Michael Ford are all in the mix.

For Weems, the only thing he can do is keep working and hope for the best.

“I’m just taking every opportunity I can get,” he said. “I’m working hard at it, trying to get better each and every practice, and just do what I can, when I can.”

Roll call

Bears linemen Jordan Mills, Matt Slauson and Kyle Long each sat out of practice. As he recovers from his shoulder injury, Conte was absent from Halas Hall altogether because of a “contagious” illness, Trestman said, though it’s nothing serious. Will Sutton rejoined the team after an absence for personal matters the first two days of camp.

Extra points

– The conclusion of Thursday’s practice marked the start of an abbreviated summer break, a month of freedom before training camp starts. Still, Trestman sensed the urgency inside the Walter Payton Center. “I thought it was an excellent conclusion of (mini-camp) today,” Trestman said. “Most of all, everyone came out of it safely. That’s what’s most important in this offseason program.”

— A report from the Chicago Tribune said the Bears have released tight end Fendi Onobun, who had three more drops in practice on Thursday, continuing an alarming trend. Trestman declined to comment on the report, any other dismissals and Onobun’s offseason.

— Jimmy Clausen won’t have to worry about getting the boot from the Bears. Trestman was pleased with his performance in mini-camp and confirmed the quarterback will be part of the team in training camp. “Jimmy has competed and done a good job for the time that he’s been here,” Trestman said. “I know he’ll be with us.” The Bears will likely only take four quarterbacks into training camp, meaning David Fales, Jordan Palmer and Jarrod Johnson were, like Clausen, each in a battle to keep their spot behind starter Jay Cutler.

— Clausen is eager to continue his opportunity with the Bears and fight for a roster spot. “It’s do or die, per se,” he said. “I just need to go out there and compete.”

— Before the Bears broke huddle for the final time in minicamp, Trestman had a message for the next month. “It’s time to get away, but it’s not a vacation,” he said. “Guys have to have a plan to optimize their strength and conditioning.”